Recent Muslim-bashing comments by Ben Carson and Donald Trump follow a path blazed by other GOP candidates in the race. Bobby Jindal earlier this year falsely asserted that several British cities have no-go zones where non-Muslims can't enter. And Rand Paul recently commented that immigrants from Muslim countries should be subjected to special scrutiny.
The barrage of anti-Muslim rhetoric in the Republican primary appeals to a very specific segment of the party's base.
"These ideas emerge, broadly speaking, from the combined Tea Party wing of politics and the Christian Right," says Frederick Carlson, senior fellow for religious liberty at Political Research Associates. "These are dynamic, overlapping elements of the GOP electorate that play an outsized role in the upcoming primaries and caucuses."
Mainstream antipathy to Muslims means that, within the party, Republicans don't pay a high price for maligning this religious group (a tiny percentage of American voters with almost no representation in the federal government.) A full 60 percent of Republicans said they viewed Islam unfavorably in a 2013 New York Times-CBS poll.
That's why Carson's comment that there should not be a Muslim President is causing his popularity to soar among Republicans, in spite of heartbreak among Muslim Americans.
"I don1t look to Dr. Ben Carson to educate us about Islam," says Duke University Professor Omid Safi, who heads the Duke Islamic Center. "But I do expect a person running for the presidency of the United States of America to be familiar with the basic facts of the American Constitution."
Instead, Carson has intensified his anti-Muslim rhetoric. He has focused on an obscure tenet of Islam to suggest that the religion pushes its followers to be untruthful.
"Taqiyya is a component of Sharia that allows, and even encourages, you to lie to achieve your goals," Carson told The Hillnewspaper, picking up on a slanderous meme popular on the right.
But, as Safi, explained to The Washington Post, this is an outrageous distortion of a precept that mostly the minority Shiite Muslims have followed when they have been in mortal danger.
"In brief, it states to value human life over declaration of faith," Safi said. "It is the proverbial question: If a Shia is being persecuted, and someone holds a gun to your head asking 'are you a Shia?' you are allowed to say 'no' in order to save a human life."
This is the context in which it has been practiced historically, as the Post points out. (Sunni Muslims did this to save their lives in Inquisition-era Spain.) The Post gave Carson its worst rating of four Pinocchios for his distortion of the facts on this issue.
But all this is besides the point for the GOP base.
"It has little to do with Islam or Muslims, in a way," Safi tells me. "It's a pathetic and vicious appeal to the most bigoted base of their party to distinguish themselves from their competitors. It's also a recognition that while similar comments against other ethnic and religious communities would carry serious penalty, demonizing Muslims carries little risk for them."
There are institutional links between the anti-Muslim crowd and the GOP that only make it more beneficial for the presidential contenders to pick on Muslims.
"One does not have to look very far to see significant connections between prominent Republican Party figures and explicitly Islamophobic groups and individuals," says Clarkson. "For example, Frank Gaffney Jr., a neoconservative Reagan-era Defense Department official, heads the Center for Security Policy and routinely host Republican figures on his radio program."
Gaffney, a once mainstream figure on the Right, has gone off the deep end in recent years with his accusations that the Obama Administration is enabling a Muslim Brotherhood takeover of the United States.
"Gaffney also speaks at conservative Republican-oriented conferences, such as the annual Values Voter Summit (sponsored by, among others, the Family Research Council and in past years the Heritage Foundation), which functions as a GOP candidate cattle call in pre-election years like this one for the Christian Right," he adds. "As a matter of fact, Trump, Carson, Huckabee, Jindal, Santorum and others are all speaking at the summit this week. Last year's summit featured multiple Islamophobic speeches."
Attacking Islam resonates deeply in this group. The Reverend Franklin Graham, the son of the legendary Billy, suggested a couple of months ago that Muslim immigration be stopped to this country. And rightwing media personalities Bill O'Reilly and Rush Limbaugh have rushed to Carson's defense.
"Linking political and religious opponents to peoples with whom the nation is at war is an old trick," says Clarkson. "And the demonization of all Muslims in the face of conflicts in the Middle East is likely to be in the tool kit of domestic political demagogues for the foreseeable future."
That's bad news for civility. The GOP has a problem with alienating Latinos, a growing piece of the electorate. The party can't win a general election without a segment of the Latino vote. But Muslims are such a small part of the U.S. population, it may be a safe bet to target them. The question is, how much bigotry will the American public put up with? The Republican candidates seem determined to find out.